This invention relates to circuits for driving gas discharge lamps, and particularly, though not exclusively, to circuits for driving fluorescent lamps.
In a typical prior art circuit for driving a plurality of fluorescent lamps, the lamps are driven from a high-frequency resonant circuit powered from a DC power source via an inverter. The lamps are typically coupled to the output of the resonant circuit via a transformer, and filaments of the lamps are provided with heating current from small individual windings on an output-coupling transformer.
Such prior art circuits typically offer low operating efficiencies. Also, the use of an output-coupling transformer adds to the cost of the circuit.